JP3651785B2 - Commutator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a commutator.
[0002]
[Prior art]
A disc-type commutator having a disc-shaped commutation surface is well-known in vehicle rotating devices such as a motor-integrated fuel pump and a starter motor. The disk-type commutator includes a separate disk-type commutator that is axially adjacent to the armature and is fixed to the rotating shaft separately from the armature, and is formed integrally with the armature. An integrated disk-type commutator (or commutator-integrated armature) in which an end portion is bent in a radial direction to form a commutator piece is known.
[0003]
In these disk-type commutators, the gap between the commutator pieces (also referred to as the gap between the commutator pieces or simply the gap) has an opening surface on the back side of the armature and is radial (including a spiral shape) in the radial direction. ). Further, in the conventional disc-type commutator, the circumferential width of this gap is minimized to increase the area of the brush contact surface (also referred to as a commutation surface) of each commutator piece and reduce the current density. It was set.
[0004]
[Problems to be solved by the invention]
The disk-type commutator described above has advantages such as shortening the required axial dimension of the commutator, but since the gap between the commutator pieces opens in the axial direction, the commutator surface of the commutator piece is cut and finished. There was a problem that the generated chips or the brush powder or foreign matter mixed after the subsequent use of the product bites into the gap and is difficult to remove. Hereinafter, foreign substances such as chips, brush powder, and dust are simply referred to as foreign substances.
[0005]
That is, in the cylindrical commutator in which the gap between the commutator pieces opens in the radially outward direction, the centrifugal force acting on the foreign material by the rotation of the commutator urges the foreign material toward the opening of the adjacent gap. Although foreign matter is unlikely to stay in the gap, the opening of the gap faces the axial direction in the disk-type commutator, so even if centrifugal force acts on the foreign matter, the foreign matter is not urged in the opening direction, so the foreign matter is difficult to remove. . If foreign matter stays in the gap, problems such as deterioration of electrical insulation between commutator pieces, abnormal wear of brushes, deterioration of rectification, and the like are likely to occur.
[0006]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a disk-type commutator that is much easier to remove foreign matter than ever before.
[0009]
[Means for Solving the Problems]
The commutator according to claim 1 is an insulating plate-like insulating plate having electrical insulation and mounted on a rotating shaft, and is in contact with or coupled to the annular plate surface of the insulating plate and is predetermined in the circumferential direction. A plurality of commutator pieces that are arranged radially around the shaft center with a gap therebetween to form an annular plate-like rectifying surface, and two commutator pieces that are adjacent to the annular plate surface of the insulating plate. In the commutator provided with a gap between the commutator pieces that is open on the commutation surface side, one of which is surrounded by three sides on the side surface,
The gap between the commutator pieces has a circumferential width that increases continuously or stepwise from the ring plate surface side of the insulating plate toward the commutation surface side of the commutator piece.
[0010]
According to the disk-type commutator of the present invention of this configuration, the gap between the commutator pieces is wider in the circumferential direction than the inner back portion in the axial direction, so that the gap falls into the gap. Foreign matter can be easily removed. That is, in the disc-type commutator, the radial length of the gap is long and the circumferential width of the gap is constant. It was not easy to remove the foreign matter from the outer peripheral surface of the disk-type commutator by acting on.
[0011]
Therefore, according to the present configuration, since the gap cross section is tapered toward the axial opening, the foreign matter in the gap causes the circumferential acceleration force F (= ma) acting on the foreign matter when the rotational speed fluctuates. Can be discharged from the gap by being biased in the axial direction toward the opening of the gap along the taper, that is, along the side surface of the commutator piece. As a result, it is possible to prevent foreign matter from staying in the gap and causing problems such as deterioration of the electrical insulation between the commutator pieces, abnormal wear of the brush, and deterioration of the rectification property. An easy disk-type commutator can be realized.
[0012]
According to a second aspect of the present invention, in the disk-type commutator according to the first aspect, a side surface facing the gap between the commutator pieces and facing the rotation direction of the commutator piece faces the gap between the commutator pieces. The commutator piece has an inclined surface that is looser than the side surface facing the direction opposite to the rotation direction, so that the foreign matter is urged further in the axial direction along the loose inclined surface during rotation. Since it becomes easy to be done, the foreign material discharge | emission property from a gap can be improved further.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the invention are illustrated by the following examples. Of course, the form of the present invention is not limited to the following examples.
[0014]
[Example 1]
An embodiment in which the commutator of the present invention is applied to a starter having a commutator-integrated armature will be described with reference to FIGS.
[0015]
FIG. 1 is a perspective view showing a commutator-integrated armature of this embodiment, wherein 1 is an armature, 2 is a disk-type commutator, 3 is a shaft, and 4 is a collar.
[0016]
The armature 1 includes an armature core 11 and an armature coil including a number of armature conductors 13 accommodated in slots 12 of the armature core 11. Although illustration of the slot cross section is omitted, each slot 12 contains two armature conductors 13 which are divided into a slot opening side and a slot inner side, that is, stacked in the radial direction. Hereinafter, the armature conductor 13 on the slot opening side is referred to as an upper layer conductor 13, and the armature conductor 13 on the inner side in the slot is referred to as a lower layer conductor 13. The upper layer conductor 13 and the lower layer conductor 13 each have a square cross section. Therefore, in FIG. 1, the upper layer conductor 13 is exposed from the slot opening of each slot 12, and the lower layer conductor 13 is hidden and cannot be seen.
[0017]
The armature coil is composed of a number of unit coils equal to the number of slots, and each unit coil is formed in a substantially U-shape and is individually provided in two slots 12 whose two sides are separated from each other by a predetermined pitch in the circumferential direction. Contained. More specifically, each coil is formed by sequentially connecting a side portion forming the upper layer conductor 13, a side portion forming the front coil end, and a side portion forming the lower layer conductor 13 (not shown).
[0018]
Furthermore, each upper layer conductor 13 protrudes from the rear side end portion of the slot 12 to the axial rear side, and is then individually joined to the outer peripheral end of each commutator piece 21 of the disk-type commutator 2. The conductor also protrudes from the rear side end of the slot 12 toward the axial rear side, and is then individually joined to the inner peripheral end of each commutator piece 21 of the disk-type commutator 2.
[0019]
Preferably, the commutator piece 21 and the upper layer conductor 13 are integrally formed. Further, the lower conductor protruding from the rear end of the slot 12 toward the axial rear side extends inward in the radial direction and reaches the inner peripheral end of each commutator piece 21 by a predetermined angle in the circumferential direction. It may be curved.
[0020]
The disc-type commutator 2 is formed in a number equal to the number of slots 12 = the number of upper layer conductors 13 and is fitted to the shaft 3 and a large number of commutator pieces 21 arranged radially (precisely spirally). 1 is formed of a ring-shaped and electrically insulating insulating plate 22 interposed between each commutator piece 21 and the rear end face of the armature core 11, and is adjacent in the circumferential direction as shown in FIG. A gap 23 having a predetermined width in the circumferential direction is provided between each commutator piece 21 to be performed. The electrically insulating collar 4 is fixedly fitted to the shaft 3 to fix the commutator piece 21 by urging the inner peripheral portion of each commutator piece 21 toward the front side in the axial direction. The commutator piece 21 is pressed against the rear end face of the armature core 11 through the insulating plate 22.
[0021]
FIG. 2 shows a front view of the commutator 2 viewed from the axial front side. After each commutator piece 21 is assembled, it is cut to make the height (axial direction) of each commutator piece 21 uniform to form a commutation surface (hatched portion in FIG. 2). Chips with oil at the time of cutting fall into the gap 23.
[0022]
For further details of this type of commutator-integrated armature, please refer to the applicant's previously filed specification.
[0023]
(Detailed structure of gap 3 of commutator 2)
The detailed structure of the gap 23 of the commutator 2 will be described with reference to FIG.
[0024]
In this embodiment, as shown in FIG. 3, the gap 23 has a circumferential width that continuously increases from the inner peripheral side toward the outer peripheral side. In particular, in this embodiment, the circumferential width a of the outer peripheral portion of the gap 23 is formed twice or more larger than the circumferential width b of the inner peripheral portion.
[0025]
In this way, the chips falling into the gap 23 are rotated by rotating the armature after the cutting, or by blowing water or air from the inner peripheral end of the gap 23 into the gap 23 at a high speed. The movement can be easily started toward the outer peripheral side of the gap 23, and as a result, it can be removed from the opening of the gap 23 to the outside from the outer peripheral end of the gap 23 or in the middle thereof. Further, even if foreign matter enters the gap 23 after the armature is used, the foreign matter is automatically removed from the gap 23 in the same manner as described above due to the centrifugal force generated by the armature rotation acting on the foreign matter. Can do.
[0026]
A detailed structure of the gap 23 of the commutator 2 will be described with reference to FIG. 4 showing a cross-sectional view taken along the line AA of FIG.
[0027]
In this embodiment, as shown in FIG. 4, the gap 23 is continuously widened from the ring plate surface 220 on the commutator piece 21 side of the insulating plate 22 toward the rectifying surface side of the commutator piece 21. t.
[0028]
In this way, the chips falling into the gap 23 can be easily opened by rotating the armature after the cutting or by blowing water or air into the gap 23 at a high speed. Can be discharged toward the side. In addition, even if a foreign object enters the gap 23 after the armature is put into use, the inertia force (F = ma) generated by the change in the armature rotation acts on the foreign object, and the foreign object is automatically generated from the gap 23 in the same manner as described above. Can be removed automatically.
(Modification)
A modification of FIG. 4 is shown in FIG.
[0029]
In this modification, the commutator piece 21a is different from the commutator piece 21 shown in FIG. 4 in the inclined shape of the side surface of the commutator piece 21a. That is, in this modification, of the pair of side surfaces 211 and 212 respectively facing the gap 23a of the commutator piece 21, the side surface 211 facing the rotation direction is inclined more gently than the side surface 212 facing the rotation direction. have.
[0030]
In this way, the foreign matter in the gap 23 rolls around the gently inclined side surface 212 during rotation and is discharged outside from the opening of the gap 23 without reducing the effective rectifying surface area of the commutator piece 21a. Is even easier.
(Modification)
In the above embodiment, the armature-integrated commutator has been described. However, it is obvious that a disk-type commutator formed separately from the armature can achieve the same effects as described above.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an armature having a commutator according to a first embodiment.
FIG. 2 is a radial front view of the commutator of FIG.
FIG. 3 is a partially enlarged view of FIG. 2;
4 is a front view taken along the line AA in FIG. 3;
FIG. 5 is a partial front view showing a modification of FIG. 4;
[Explanation of symbols]
1 Armature 2 Commutator 3 Shaft 4 Collar 11 Armature Iron Core 12 Slot 21 Commutator Piece 22 Insulating Plate 23 Gap

Claims (2)

A ring-shaped insulating plate having electrical insulation and mounted on a rotating shaft;
A plurality of commutator pieces that are in contact with or coupled to the annular plate surface of the insulating plate and are radially arranged around the shaft center with a predetermined gap therebetween in the circumferential direction to form an annular plate-like rectifying surface as a whole. When,
The gap between the commutator pieces, one of which is surrounded by three sides of the ring plate surface of the insulating plate and the side surfaces of the two commutator pieces adjacent to each other and opened to the commutation surface side;
In a commutator comprising:
The gap between the commutator pieces has a circumferential width that increases continuously or stepwise from the ring plate surface side of the insulating plate toward the commutation surface side of the commutator piece. Child. The commutator according to claim 1 ,
The side surface facing the gap between the commutator pieces and facing the rotation direction of the commutator piece is looser than the side surface facing the gap between the commutator pieces and facing the rotation direction of the commutator piece. A commutator having an inclined surface.

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